Isaac Newton · every age

What was Isaac Newton doing at 70?

Invented calculus and gravity theory in a plague year at 23

1. c. 1713

   Second edition of the Principia at 70

   He refused to frame hypotheses about the cause of gravity.

   Source: en.wikipedia.org

Portrait: Portrait: Godfrey Kneller (1689), public domain, via Wikimedia Commons · source